The present invention relates to a new radome design with tailorable through thickness reinforcement (TTR) that increases mechanical durability of the reinforced radome against an applied force, as well as methods of making the same.
A number of systems, including radar and antennas, depend on radomes to protect them from aero-loading, handling, and the environment. Radomes have been known in the art for more than a half century. As systems become more sensitive, the effects of the radome become increasingly important to system performance.
In some cases, the balance between mechanical and radio frequency (RF) performance becomes difficult to attain with a robust design that provides long service life. This is the age-old problem that has challenged engineers from the beginning: creating a radome that is transparent to RF electromagnetic (EM) radiation, while at the same time, having the durability to withstand its environment and protect sensitive radar components. As radar capability becomes increasingly needed in harsher environments, such as on aircraft, on ships, in remote locations with severe climates, and extra planetary travel, more robust, durable radomes are needed. To satisfy this need, alternative radome designs must allow for greater mechanical durability while maintaining sensitive RF performance across the entire structure.
Currently, sandwich-structure, composite radome designs have remained essentially unchanged for decades. Honeycomb and foam core construction are used as needed for RF and mechanical performance, but are progressively underperforming due to the greater sensitivity of RF systems and increasing environmental stressors. To solve this problem, this application discloses the incorporation of TTR (which may include monolithic or composite rods, or fibers, fiber bundle, or tows which can be impregnated to yield composite structures, such as pins, that traverse the core of the radome) into foam-core sandwich composites. The incorporation of TTR has been shown to alter the mechanical properties as a function of orientation, density, termination point, and other physical and chemical characteristics of the pins or thread. This approach was investigated and found to be particularly advantageous when applied to radomes. After incorporating TTR with the radome structure, the radome structure was able to bear load beyond the ultimate strength of the material and required significant additional deflection to reach ultimate failure.
According to an illustrative embodiment of the present disclosure, a radome comprising a foam or honeycomb core that is sandwiched between two skins may be reinforced with pins that run through the core, orthogonal to the skins, wherein the pins are comprised of quartz, alumina, or another element or compound with similar characteristics and properties.
According to a further illustrative embodiment, a radome comprising a foam or honeycomb core that is sandwiched between two skins may be reinforced with pins that run through the core, where the pins may be placed at varying angles through the core so as to provide greater durability to external forces, e.g. sheer force, and wherein the pins are comprised of quartz, alumina, aramid, or another element or compound with similar characteristics and properties.
According to a further illustrative embodiment of the present disclosure, a radome comprising a foam or honeycomb core sandwiched between two skins may be reinforced with a thread or fiber/tow, which may or not be one continuous strand, wherein the thread runs through the core and may or may not run through the skins.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.